Real simulator of Biathlon shooting.
You need 2 modern iOS devices - new iPad and new iPhone.

Download app to both devices.
Run app on iPad (BLE 4.0 compatible) - it is target.
Use landscape mode with right home button.
Run app on iPhone (BLE 4.0 compatible) - it is rifle.
Also use landscape mode with right home button.
Targeting iPad - keep distance 30 - 90 sm.
Touch iPhone screen to shooting.

Try to be number one and enjoy.
See example how to play at youtube http://youtu.be/EajlMSwE5P0